The openstackclient is the preferred CLI for OpenStack
environments and should be used instead of novaclient.

* Create packet.md

* Update README.md

* Update README.md

* Update packet.md

download the latest version

* Update packet.md

* 30MiB for gpu-device-plugin

* use vars for easier configuration

Upstream Changes:

  - weave 2.5.1 (https://github.com/weaveworks/weave/releases/tag/v2.5.1)

Our Changes:

  - Sync templates with upstream changes

* added hardware requirements in README.md

* added hardware requirements in README.md

* fact gathering should run only once per node
* eliminate ansible version check, it is at the beginning of each
  playbook

The lastest version of ubuntu-nvidia-driver-installer contains a fix for
https://github.com/GoogleCloudPlatform/container-engine-accelerators/issues/90
which causes the installer pod to crash when driver is already loaded.

This was already approved in #4106 but there are CI issues
with that PR due to references to kubernetes incubator.

After upgrading to Kubespray 2.8.1 with Kubeadm enabled Rook
Ceph volume provision failed due to the flexvolume plugin dir not
being correct. Adding the var fixed the issue

Useful if the default 20GB is not enough in cases where you are using
the local path provisioner of rancher for example

because of etc-kubernetes-manifests not empty.

Add update server field in kube-proxy kubeconfig

* Adding ability to maintain existing Encryption Secrets at Rest.

If secrets_encryption.yaml is present it will not be overriten with a new kube_encrypt_token.

This should allow for it to be set ahead of a playbook running or maintain it if cluster.yml is ran on the same cluster and the ansible host does not have access to the secrets.

* Setting existing kube_encrypt_token across all master nodes in case it was missing in one or more nodes.

For some reason 18.09 packages are now prefixed with `5:` in the download.docker.com apt repos
Followup to #4236

This fixes an issue where the `nodename` in calico's cni config json can fall out of sync with the k8s node name used by the calico pod if `kube_override_hostname` is set

Currently, the task `container_download | download images for kubeadm config images` fetches etcd image even though it's not required (etcd is bootstrapped by kubespray, not kubeadm).

`kubeadm-images.yaml` is only a subset of `kubeadm-config.yaml`, therefore ``kubeadm config images pull` will try to get all this list (including etcd)

```
# kubeadm config images list --config /etc/kubernetes/kubeadm-images.yaml
k8s.gcr.io/kube-apiserver:v1.13.2
k8s.gcr.io/kube-controller-manager:v1.13.2
k8s.gcr.io/kube-scheduler:v1.13.2
k8s.gcr.io/kube-proxy:v1.13.2
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.6
```

When using the `kubeadm-config.yaml` though, it doesn't list etcd image:

```
# kubeadm config images list --config /etc/kubernetes/kubeadm-config.yaml
k8s.gcr.io/kube-apiserver:v1.13.2
k8s.gcr.io/kube-controller-manager:v1.13.2
k8s.gcr.io/kube-scheduler:v1.13.2
k8s.gcr.io/kube-proxy:v1.13.2
k8s.gcr.io/pause:3.1
k8s.gcr.io/coredns:1.2.6
```

This change just adds the etcd endpoints in the `kubeadm-images.yaml` to give a hint to kubeadm it doesn't need etcd image for its boostrapping as etcd is "external".
I confess it is a ugly hack, a better way would be to use a single `kubeadm-config.yaml` for both tasks, but they are triggered by different roles (`kubeadm-images.yaml` is used by download, `kubeadm-config.yaml` by kubernetes/master) at different steps and I didn't want to refactor too many things to prevent breakage. 

This is specially useful for offline installation where a whitelist of container images is mirrored on a local private container registry. `k8s.gcr.io/etcd` and `quay.io/coreos/etcd`  are two different repositories hosting the same images but using *different tags*! 
* coreos/etcd:v3.2.24   
* k8s.gcr.io/etcd:3.2.24 (note the missing 'v' in the tag name)

This updates docker 18.06 and 18.09 with the two patches released
yesterday to address the new runc exploit. Details here:
https://kubernetes.io/blog/2019/02/11/runc-and-cve-2019-5736/

Omit does not work in the context of yum_repository proxy. The ansible documentation specifies to use _none_ to disable the global proxy setting. (#4225)